Class: Gem::Resolver
- Inherits:
-
Object
- Object
- Gem::Resolver
- Defined in:
- lib/rubygems/resolver.rb
Overview
Given a set of Gem::Dependency objects as needed
and a way to query the set of available specs via set
, calculates a set of ActivationRequest objects which indicate all the specs that should be activated to meet the all the requirements.
Defined Under Namespace
Classes: APISet, APISpecification, ActivationRequest, BestSet, ComposedSet, Conflict, CurrentSet, DependencyRequest, GitSet, GitSpecification, IndexSet, IndexSpecification, InstalledSpecification, InstallerSet, LocalSpecification, LockSet, LockSpecification, RequirementList, Set, SpecSpecification, Specification, State, Stats, VendorSet, VendorSpecification
Constant Summary collapse
- DEBUG_RESOLVER =
If the DEBUG_RESOLVER environment variable is set then debugging mode is enabled for the resolver. This will display information about the state of the resolver while a set of dependencies is being resolved.
!ENV['DEBUG_RESOLVER'].nil?
- DependencyConflict =
TODO: Remove in RubyGems 3
Gem::Resolver::Conflict
Instance Attribute Summary collapse
-
#conflicts ⇒ Object
readonly
Contains all the conflicts encountered while doing resolution.
-
#development ⇒ Object
Set to true if all development dependencies should be considered.
-
#development_shallow ⇒ Object
Set to true if immediate development dependencies should be considered.
-
#ignore_dependencies ⇒ Object
When true, no dependencies are looked up for requested gems.
-
#missing ⇒ Object
readonly
List of dependencies that could not be found in the configured sources.
-
#skip_gems ⇒ Object
Hash of gems to skip resolution.
-
#soft_missing ⇒ Object
When a missing dependency, don’t stop.
-
#stats ⇒ Object
readonly
Returns the value of attribute stats.
Class Method Summary collapse
-
.compose_sets(*sets) ⇒ Object
Combines
sets
into a ComposedSet that allows specification lookup in a uniform manner. -
.for_current_gems(needed) ⇒ Object
Creates a Resolver that queries only against the already installed gems for the
needed
dependencies.
Instance Method Summary collapse
-
#activation_request(dep, possible) ⇒ Object
Creates an ActivationRequest for the given
dep
and the lastpossible
specification. -
#explain(stage, *data) ⇒ Object
:nodoc:.
-
#explain_list(stage) ⇒ Object
:nodoc:.
-
#find_possible(dependency) ⇒ Object
Extracts the specifications that may be able to fulfill
dependency
and returns those that match the local platform and all those that match. -
#handle_conflict(dep, existing) ⇒ Object
:nodoc:.
-
#initialize(needed, set = nil) ⇒ Resolver
constructor
Create Resolver object which will resolve the tree starting with
needed
Dependency objects. -
#requests(s, act, reqs = nil) ⇒ Object
:nodoc:.
-
#resolve ⇒ Object
Proceed with resolution! Returns an array of ActivationRequest objects.
-
#resolve_for(needed, specs) ⇒ Object
The meat of the algorithm.
-
#resolve_for_conflict(needed, specs, state) ⇒ Object
Rewinds
needed
andspecs
to a previous state instate
for a conflict betweendep
andexisting
. -
#resolve_for_multiple(needed, specs, states, dep, possible) ⇒ Object
There are multiple
possible
specifications for thisdep
. -
#resolve_for_single(needed, specs, dep, possible) ⇒ Object
Add the spec from the
possible
list tospecs
and process the spec’s dependencies by adding them toneeded
. -
#resolve_for_zero(dep, platform_mismatch) ⇒ Object
When there are no possible specifications for
dep
our work is done. -
#select_local_platforms(specs) ⇒ Object
Returns the gems in
specs
that match the local platform.
Constructor Details
#initialize(needed, set = nil) ⇒ Resolver
Create Resolver object which will resolve the tree starting with needed
Dependency objects.
set
is an object that provides where to look for specifications to satisfy the Dependencies. This defaults to IndexSet, which will query rubygems.org.
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# File 'lib/rubygems/resolver.rb', line 109 def initialize needed, set = nil @set = set || Gem::Resolver::IndexSet.new @needed = needed @conflicts = [] @development = false @development_shallow = false @ignore_dependencies = false @missing = [] @skip_gems = {} @soft_missing = false @stats = Gem::Resolver::Stats.new end |
Instance Attribute Details
#conflicts ⇒ Object (readonly)
Contains all the conflicts encountered while doing resolution
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# File 'lib/rubygems/resolver.rb', line 28 def conflicts @conflicts end |
#development ⇒ Object
Set to true if all development dependencies should be considered.
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# File 'lib/rubygems/resolver.rb', line 33 def development @development end |
#development_shallow ⇒ Object
Set to true if immediate development dependencies should be considered.
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# File 'lib/rubygems/resolver.rb', line 38 def development_shallow @development_shallow end |
#ignore_dependencies ⇒ Object
When true, no dependencies are looked up for requested gems.
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# File 'lib/rubygems/resolver.rb', line 43 def ignore_dependencies @ignore_dependencies end |
#missing ⇒ Object (readonly)
List of dependencies that could not be found in the configured sources.
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# File 'lib/rubygems/resolver.rb', line 48 def missing @missing end |
#skip_gems ⇒ Object
Hash of gems to skip resolution. Keyed by gem name, with arrays of gem specifications as values.
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# File 'lib/rubygems/resolver.rb', line 56 def skip_gems @skip_gems end |
#soft_missing ⇒ Object
When a missing dependency, don’t stop. Just go on and record what was missing.
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# File 'lib/rubygems/resolver.rb', line 62 def soft_missing @soft_missing end |
#stats ⇒ Object (readonly)
Returns the value of attribute stats.
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# File 'lib/rubygems/resolver.rb', line 50 def stats @stats end |
Class Method Details
.compose_sets(*sets) ⇒ Object
Combines sets
into a ComposedSet that allows specification lookup in a uniform manner. If one of the sets
is itself a ComposedSet its sets are flattened into the result ComposedSet.
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# File 'lib/rubygems/resolver.rb', line 69 def self.compose_sets *sets sets.compact! sets = sets.map do |set| case set when Gem::Resolver::BestSet then set when Gem::Resolver::ComposedSet then set.sets else set end end.flatten case sets.length when 0 then raise ArgumentError, 'one set in the composition must be non-nil' when 1 then sets.first else Gem::Resolver::ComposedSet.new(*sets) end end |
.for_current_gems(needed) ⇒ Object
Creates a Resolver that queries only against the already installed gems for the needed
dependencies.
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# File 'lib/rubygems/resolver.rb', line 97 def self.for_current_gems needed new needed, Gem::Resolver::CurrentSet.new end |
Instance Method Details
#activation_request(dep, possible) ⇒ Object
Creates an ActivationRequest for the given dep
and the last possible
specification.
Returns the Specification and the ActivationRequest
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# File 'lib/rubygems/resolver.rb', line 144 def activation_request dep, possible # :nodoc: spec = possible.pop explain :activate, [spec.full_name, possible.size] explain :possible, possible activation_request = Gem::Resolver::ActivationRequest.new spec, dep, possible return spec, activation_request end |
#explain(stage, *data) ⇒ Object
:nodoc:
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# File 'lib/rubygems/resolver.rb', line 123 def explain stage, *data # :nodoc: return unless DEBUG_RESOLVER d = data.map { |x| x.pretty_inspect }.join(", ") $stderr.printf "%10s %s\n", stage.to_s.upcase, d end |
#explain_list(stage) ⇒ Object
:nodoc:
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# File 'lib/rubygems/resolver.rb', line 130 def explain_list stage # :nodoc: return unless DEBUG_RESOLVER data = yield $stderr.printf "%10s (%d entries)\n", stage.to_s.upcase, data.size PP.pp data, $stderr unless data.empty? end |
#find_possible(dependency) ⇒ Object
Extracts the specifications that may be able to fulfill dependency
and returns those that match the local platform and all those that match.
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# File 'lib/rubygems/resolver.rb', line 208 def find_possible dependency # :nodoc: all = @set.find_all dependency if (skip_dep_gems = skip_gems[dependency.name]) && !skip_dep_gems.empty? matching = all.select do |api_spec| skip_dep_gems.any? { |s| api_spec.version == s.version } end all = matching unless matching.empty? end matching_platform = select_local_platforms all return matching_platform, all end |
#handle_conflict(dep, existing) ⇒ Object
:nodoc:
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# File 'lib/rubygems/resolver.rb', line 224 def handle_conflict(dep, existing) # :nodoc: # There is a conflict! We return the conflict object which will be seen by # the caller and be handled at the right level. # If the existing activation indicates that there are other possibles for # it, then issue the conflict on the dependency for the activation itself. # Otherwise, if there was a requester, issue it on the requester's # request itself. # Finally, if the existing request has no requester (toplevel) unwind to # it anyway. if existing.others_possible? conflict = Gem::Resolver::Conflict.new dep, existing elsif dep.requester depreq = dep.requester.request conflict = Gem::Resolver::Conflict.new depreq, existing, dep elsif existing.request.requester.nil? conflict = Gem::Resolver::Conflict.new dep, existing else raise Gem::DependencyError, "Unable to figure out how to unwind conflict" end @conflicts << conflict unless @conflicts.include? conflict return conflict end |
#requests(s, act, reqs = nil) ⇒ Object
:nodoc:
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# File 'lib/rubygems/resolver.rb', line 156 def requests s, act, reqs=nil # :nodoc: return reqs if @ignore_dependencies s.fetch_development_dependencies if @development s.dependencies.reverse_each do |d| next if d.type == :development and not @development next if d.type == :development and @development_shallow and act.development? next if d.type == :development and @development_shallow and act.parent reqs.add Gem::Resolver::DependencyRequest.new(d, act) @stats.requirement! end @set.prefetch reqs @stats.record_requirements reqs reqs end |
#resolve ⇒ Object
Proceed with resolution! Returns an array of ActivationRequest objects.
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# File 'lib/rubygems/resolver.rb', line 182 def resolve @conflicts = [] needed = Gem::Resolver::RequirementList.new @needed.reverse_each do |n| request = Gem::Resolver::DependencyRequest.new n, nil needed.add request @stats.requirement! end @stats.record_requirements needed res = resolve_for needed, nil raise Gem::DependencyResolutionError, res if res.kind_of? Gem::Resolver::Conflict res.to_a end |
#resolve_for(needed, specs) ⇒ Object
The meat of the algorithm. Given needed
DependencyRequest objects and specs
being a list to ActivationRequest, calculate a new list of ActivationRequest objects.
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# File 'lib/rubygems/resolver.rb', line 294 def resolve_for needed, specs # :nodoc: # The State objects that are used to attempt the activation tree. states = [] while !needed.empty? @stats.iteration! dep = needed.remove explain :try, [dep, dep.requester ? dep.requester.request : :toplevel] explain_list(:next5) { needed.next5 } explain_list(:specs) { Array(specs).map { |x| x.full_name }.sort } # If there is already a spec activated for the requested name... if specs && existing = specs.find { |s| dep.name == s.name } # then we're done since this new dep matches the existing spec. next if dep.matches_spec? existing conflict = handle_conflict dep, existing return conflict unless dep.requester explain :conflict, dep, :existing, existing.full_name depreq = dep.requester.request state = nil until states.empty? x = states.pop i = existing.request.requester explain :consider, x.spec.full_name, [depreq.name, dep.name, i ? i.name : :top] if x.spec.name == depreq.name or x.spec.name == dep.name or (i && (i.name == x.spec.name)) explain :found, x.spec.full_name state = x break end end return conflict unless state @stats.backtracking! needed, specs = resolve_for_conflict needed, specs, state states << state unless state.possibles.empty? next end matching, all = find_possible dep case matching.size when 0 resolve_for_zero dep, all when 1 needed, specs = resolve_for_single needed, specs, dep, matching else needed, specs = resolve_for_multiple needed, specs, states, dep, matching end end specs end |
#resolve_for_conflict(needed, specs, state) ⇒ Object
Rewinds needed
and specs
to a previous state in state
for a conflict between dep
and existing
.
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# File 'lib/rubygems/resolver.rb', line 367 def resolve_for_conflict needed, specs, state # :nodoc: # We exhausted the possibles so it's definitely not going to work out, # bail out. raise Gem::ImpossibleDependenciesError.new state.dep, state.conflicts if state.possibles.empty? # Retry resolution with this spec and add it's dependencies spec, act = activation_request state.dep, state.possibles needed = requests spec, act, state.needed.dup specs = Gem::List.prepend state.specs, act return needed, specs end |
#resolve_for_multiple(needed, specs, states, dep, possible) ⇒ Object
There are multiple possible
specifications for this dep
. Updates needed
, specs
and states
for further resolution of the possible
choices.
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# File 'lib/rubygems/resolver.rb', line 387 def resolve_for_multiple needed, specs, states, dep, possible # :nodoc: # Sort them so that we try the highest versions first. possible = possible.sort_by do |s| [s.source, s.version, s.platform == Gem::Platform::RUBY ? -1 : 1] end spec, act = activation_request dep, possible # We may need to try all of +possible+, so we setup state to unwind back # to current +needed+ and +specs+ so we can try another. This is code is # what makes conflict resolution possible. states << State.new(needed.dup, specs, dep, spec, possible, []) @stats.record_depth states explain :states, states.map { |s| s.dep } needed = requests spec, act, needed specs = Gem::List.prepend specs, act return needed, specs end |
#resolve_for_single(needed, specs, dep, possible) ⇒ Object
Add the spec from the possible
list to specs
and process the spec’s dependencies by adding them to needed
.
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# File 'lib/rubygems/resolver.rb', line 414 def resolve_for_single needed, specs, dep, possible # :nodoc: spec, act = activation_request dep, possible specs = Gem::List.prepend specs, act # Put the deps for at the beginning of needed # rather than the end to match the depth first # searching done by the multiple case code below. # # This keeps the error messages consistent. needed = requests spec, act, needed return needed, specs end |
#resolve_for_zero(dep, platform_mismatch) ⇒ Object
When there are no possible specifications for dep
our work is done.
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# File 'lib/rubygems/resolver.rb', line 432 def resolve_for_zero dep, platform_mismatch # :nodoc: @missing << dep unless @soft_missing exc = Gem::UnsatisfiableDependencyError.new dep, platform_mismatch exc.errors = @set.errors raise exc end end |
#select_local_platforms(specs) ⇒ Object
Returns the gems in specs
that match the local platform.
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# File 'lib/rubygems/resolver.rb', line 446 def select_local_platforms specs # :nodoc: specs.select do |spec| Gem::Platform.installable? spec end end |